To meet a requirement of a user equipment (UE) for an increasingly high data transmission rate, a multiple-input multiple-output (MIMO) technology is widely used in third generation (3G,) and next generation communications systems. A multi-antenna technology is an important constituent part of the MIMO technology.
Beams in different shapes and directions may be formed in space by performing weighting processing on a to-be-transmitted signal by using the multi-antenna technology, so as to adapt to demands on transmission of different signals. For example, a wide beam and a narrow beam may be formed through beamwidth division, where the wide beam may be used for transmitting a downlink signal, such as a downlink common channel signal. When the wide beam is used, beam transmission gains are small, and especially in a multi-antenna system with a relatively large-scale antenna array, coverage of transmitted signals is limited.